. >> kirit, our thanks to you. >>> on this sunday, a swelling crowd at the vatican for one of pope benedict's final appearances. just as we learn tonight of jockeying among the cardinals of the vatican and of the bold warning. cardinals will be told they will not be allowed to tweet when they arrive to choose the new pope. david wright reporting from the vatican. david? >> reporter: good evening, david. it's late, but the lights are on tonight in the pope's apartment. just look up there. they seem to be the only ones on. perhaps he's packing up. earlier today as he addressed the faithful, he didn't even acknowledge his imminent departure, but the crowd sure did. at least 50,000 roman catholics came to say goodbye. but pope benedict kept it strictly business as usual. even though he will appear in that window just one more time, before he makes way for someone else. >> the crowd was here for benedict today and it matters probably more to them than to him. >> reporter: even before this pope has fully said his goodbyes, behind the scenes the focus has already turned to choosing his successor.